Dragging equipment detecting system for railroads



July 21, 1959 L. w. wlGH'r DRAGGING EQUIPMENT DETECTING SYSTEM FOR RAILROADS Filed Aug. 31, 1954 2 Sheets-Sheet 1 i I l I l 1 l 1 l H m40 Pwd,...

INVENTOR. l.. W. Wl G HT W7 HIS ATTORNEY `July 2l, 1959 w. WIGHT 2,896,059

DRAGGING EQUIPMENT DETECTING SYSTEM FOR RAILROADS Filed Aug. 31, 1954 I 2 Sheets-Sheet 2 HIS ATTORNEY United States Patent vOl Patented .July 2,1, 1959.

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DRAGGING EQUIPMENT DETECTING SYSTEM FOR RAILROADS Leland W. Wight, Rochester, N.Y., assignor to General 'Railway Signal Company, Rochester, N.Y.

Application August 31, 1954, Serial No. 453,180

A5 Claims. (Cl. 246-169) This invention relates to dragging equipment 'detecting systems for railroads, and it more'particularly pertains to systems for indicating on a train when that train has equipment dragging.

Equipment dragging beneath cars often causes derailment directly, or indirectly by damage to track apparatus. It is, therefore, desirable to check trains for dragging equipment from time to time vas they progress along the trackway and advise the trainmen when there is equipment dragging.

The system according to the present invention contemplates the disposition of detector barriers in the trackway at frequently spaced intervals, together with associated trackway inductors which are normally shunted but are unshunted in response to actuation ofthe detector barrier at the associated location. Inductive receivers are carried by the trains passing over the inductors preferably near the rear ends of the trains, these receivers being operable to indicate when an open inductor is passed over, and thus indicate to the trainmen that equipment has been detected that is dragging beneath the train. The detection of dragging equipment is stored by the unshunting of an inductor until a receiver on the train passes over the inductor. At this time, the wayside detecting apparatus is automatically reset so that it is in condition for detection of equipment that may be dragging beneath the next train to pass over the barrier. The inductors are preferably disposed between the track rails on single track railroads so that they can inductively actuate a receiver on a train proceeding in either direction.

On object of the present invention is to indicate on a train immediately after passing over a dragging equipment detector barrier if that train has equipment dragging.

Another object of the present invention is to automatically reset dragging equipment vdetecting means immediately after the receiver on the last car of a train has passed over an associated inductor.

Another object of the present invention is to require the presence of a train in track sections on both sides of an inductor at the time of actuation of an associated dragging equipment detector barrier in order that the actuation of that barrier may be eective to unshunt the inductor.

Another object of the present invention is to provide a plurality of dragging equipment detector barriers spaced along a stretch of track and inductively indicate on a train when dragging equipment of that train has actuated any one of the detector barriers.

Other objects, purposes and characteristic features of the present invention will be in part obvious from the accompanyingdrawings and yin part pointed out as the description of the invention progresses.

In describingtheinvention in detail, referenceis made to the 'accompanying drawings in which like reference characters are used to designate correspondingapparatus throughout the several Lviews, andlin which:

Fig. l illustrates trackway associated apparatus for one embodiment of the dragging equipment detector system provided by the present invention;

Fig. 2 illustrates train carried receiving and indicating apparatus subject to actuation 'by the trackway apparatus of Fig. l;

Fig. 3 illustrates the structure of a typical detector barrier and circuit controller that can be made subject to actuation by equipment dragging beneath a train passing over the barrier in either direction;

Fig. 4 is an elevational sectional view of a circuit controller which has its contacts actuated in accordance with the actuation of an associated detector barrier; and

Fig. 5 illustrates typical electronic receiving apparatus that can be carried by a train to render a detector relay responsive upon the train passing over an unshunted inductor. For the purpose of simplifying the disclosure of the present invention, the organization of the system according to the present invention is illustrated schematically in a manner which more particularly facilitates the disclosure of the mode of operation and the principles involved in the present invention, rather than for the purpose of illustrating ythe specific construction and arrangement of parts that would be employed in practice. The symbols (-l-) and have been used to indicate connections to the respective positive and negative terminals of suitable batteries or other sources of direct current.

The trackway illustrated in Fig. l for this embodiment of the present invention is assumed to have traffic in both directions and is divided into track sections 1T, 2T, 3T and 4T, each of the track sections having a suitable track circuit controlling a track relay TR. The track circuits are arranged with the track relays TR associated with pairs of adjoining track sections being located .at the adjoining ends. These track circuits may be the same track circuits that are used for the control of wayside signals, or they may be provided for the specic purposes of the present invention on railroads that have no track circuit controlled signalling systems. If provided solely for the specific purposes of the present invention, the track sections can be relatively short in length, a pair of adjoining short track sections being associated with each detector barrier location. In this case, the length of the track sections is only required to be such as to provide for dependable shunting upon the passage of trains. The minimum length should be such that there will be no possibility of a track section being bridged by the respective trucks of the longest car to pass over the trackway.

Disposed across the trackway at spaced locations are detector barriers lDB and ZDB. The spacing of these barriers DB is in accordance with the desired frequency of checking the trains for dragging equipment. The specic structure of the barriers DB can be as is disclosed, for example, in the patent to G. H. Dryden, No. 2,581,084, dated January 1, 1952.

As is illustrated in Fig. 3, the barrier lDB, for exam-ple, is supported by end brackets 10 which in turn are secured to the ends of a pair of ties 11. The barrier IDB is connected by an operating rod 12 through a spring biasing mechanism BM to a shaft 13 of a suitable circuit controller lDC. The biasing springs 14 and 15 of the biasing mechanism BM makes the barrier IDB yieldable by rotation-in either direction from a vertical position, and also cause the automatic restoration of the barrier to its normal vvertical position when the dragging equipment has passed, as disclosed in the above-mentioned Dryden Patent No. .2,581,084, dated January l, 1952.

The circuit controller IDC, for example, is preferably modified from-the circuit controller disclosed in the Dryden Patent No. 2,581,084 as is `disclosed in Fig. 4 so that contactngers are openedby actuation of the associated` barrier 1DB in either direction from its vertical position as disposed across the trackway. This mode of operation is accomplished in accordance with notches 16 and 17 in the operating shaft 13 of the circuit controller 1DC which permits the dropping of the rocker 18 and the opening of the contact points 19 and 20 upon movement of the shaft 13 from its normal position (as illustrated) axially in either direction by actuation ofthe barrier lDB.

A detector stick relay DES is provided for each of the barriers DB for the purpose of detecting and storing a condition involving the momentary actuation of the associated barrier DB.

Communication of an indication of dragging equipment to the trainmen may be accomplished by any suitable electrical or mechanical automatic means, such, for example, as by an inductive control system disclosed in the application of Hugh C. Kendall, Ser. No. 261,435, tiled December 13, 1951, now Patent No. 2,768,286, dated October 23, 1956. Assuming this type of control system, a track located tuned inductor TI is provided for each detector barrier DB and is preferably located between the track rails at the point of junction of a pair of adjoining track sections. The respective inductors TI are selectively tuned and detuned by respective unshunting and shunting inductor windings 21, each inductor being provided with a second winding 22 that is always shunted by a condenser 23.

Each train has its last car, which is generally the caboose of a freight train, equipped with a receiving inductor RI which is disposed beneath the car to cooperate inductively with the inductors TI located in the trackway. Suitable train carried receiving apparatus is provided in association with each train carried inductor RI, along with a magnetic stick indication relay DEK so that the relay DEK is actuated whenever the associated receiving inductor RI passes over a tuned inductor TI. This control can be accomplished as is disclosed in the above mentioned Kendall application by the receiving apparatus comprising an oscillator having the associated receiving inductor RI included in a load circuit. When receiving and track inductors RI and TI are inductively coupled and tuned to substantially the same frequency, the relay DEK becomes actuated.

With reference to Fig. 5, each of the oscillators includes an electron tube T1 which has among its circuit components, an associated pick-up inductor RI. Each of the oscillators is preferably crystal controlled by a crystal CR to provide a stable operating frequency, and the pick-up inductor RI is a part of the tuned load circuit for the oscillator. The alternating current output of each of the oscillators is amplified by amplifier tubes T2 and T3, rectified by a tube T4, and applied as ltered direct current to the upper winding of relay DEK with a polarity opposing the polarity of energization of the lower winding of relay DEK as is indicated in Fig. 2. This apparatus disclosed in Fig. is as shown in the Patent No. 2,768,286, dated October 23, 1956, above mentioned.

Each relay DEK has associated therewith a reset button RES, an indicator lamp DE, and a bell DX.

Having thus described the general organization of the system, consideration will now be given to the specic circuit organization when considering the mode of operation of the system.

Normally, with the trackway unoccupied, the track relays 1TR, ZTR, STR and 4TR are all maintained in their engerized positions by their associated track batteries TB. This provides for energization of relay lDES through front contacts 24 and 25 of relays 1TR and ZTR, respectively connected in multiple. Relay ZDES is sim ilarly energized through front contacts 26 and 27 of relays STR and 4T R respectively connected in multiple.

Relay lDES is also maintained energized by a stick circuit that is normally closed through contact points 19 and 20 of the circuit controller IDC and front contact 2 of relay lDES, 4Relay 2 DES has a similar stick circuit.

Should the barrier 1DB, for example, become actuated in an unauthorized manner as by being actuated by someone walking along the trackway, with no trains present, the relay lDES is not dropped away by such actuation even though its stick circuit is momentarily opened. This is because relay IDES is held up by reason of the track relays 1TR and ZTR being picked up to apply energy at their respective contacts 24 and 25. Furthermore, if one of these track relays is dropped away by the presence of a train in its associated track section and the other relay is picked up, relay lDES is maintained energized, irrespective of actuation of the barrier 1DB. Thus, it is required that both track relays 1TR and ZTR must be dropped away before actuation of the barrier IDB can become effective to drop the relay 1DES. This in eect means in most cases that a train must be over a detector barrier DB in order that actuation of the barrier may be eiective to drop the associated relay DES.

The windings 21 of the track inductors TI are normally shunted in accordance with the normally energized condition ofthe associated relay DES. Thus, the winding 21 of the inductor 1TI, for example, is normally shunted bythe closure of front contact 29 of relay lDES.

In the train-carried receiving equipment, the magnetic stick relay DEK is normally in its dropped away position, and it becomes picked up only when the train-carried inductor RI passes over a trackway inductor TT which is tuned to resonate substantially at the frequency of the receiving oscillator by reason of its winding 21 being open. Thus, the magnetic stick relay DEK receives a pulse of energy to cause this relay to be picked up whenever the receiver RI is inductively coupled to a tuned resonant inductor TT.

To consider the mode of operation of the system for detection of dragging equipment upon passage of a train, it will be assumed that a train carrying the receiving equipment on its last car as illustrated in Fig. 2 progresses to the right through the stretch of track illustrated in Fig. l, and that equipment dragging from beneath the train actuates the barrier IDB. Because of the track relays 1TR and ZTR both being in their dropped away positions at this time, the momentary opening of the contact points 19 and 20 of the circuit controller IDC causes the dropping away of relay 1DES, and the dropping away of this relay unshunts the winding 21 of the track inductor 1TI by the opening of front contact 29.

After the dropping of the detector relay 1DES by the actuation of the barrier IDB, this relay remains in its dropped away position (assuming trailic direction is to the right), until the track section 1T becomes unoccupied in the rear of the train and the track relay 1TR becomes picked up to close front contact 24, and thus provide for the picking up of the relay 1DES.

When the train progresses further along the trackway, upon the receiver RI becoming inductively coupled to the resonant track inductor 1TI, an additional load is put on the receiving apparatus, and the receiving apparatus provides for the momentary energization of the magnetic stick relay DEK so that this relay is picked up.

When once picked up, the relay DEK is maintained in its picked up position by its magnetic stick characteristics. The picking up of this relay provides both visual and audible indications that there is equipment dragging beneath the train by the energization of the lamp DE and the bell DX through front contact 30 of relay DEK. These indications are vmaintained eiective until the condition is acknowledged by a trainmain upon actuation of the reset button RES.

The actuation of the reset button RES, with the magnetic stick relay DEK picked up, is elective through front contact 31 to energize the lower winding of relay DEK with a polarity to drive the magnetic stick relay DEK to its dropped away position. This actuation of relay DEK opens its vown circuit at front Contact 31, and energy is removed by the opening of front contact 30 from the indicator lamp D and the bell DX. Thus the traincarried receiving equipment is restored to its normal condition.

When the presence of dragging equipment has been detected and indicated to a trainman, it is assumed that the train will be brought to a stop by reason of the trainrnan signalling the engineer, applying the brakes, or communicating by train communication radio with the engineer or by any other suitable communication means. After the train has stopped, examination of the dragging equipment can determine as to what disposition is to be made of the faulty car, and the car can be set out of the train at a suitable siding if necessary.

inasmuch as dragging equipment is liable to occur at any particular point in the route of the train, it can very well be that a train may pass over the barrier 1DB without having any equipment dragging but equipment may be dragging by the time the train passes over the next barrier in advance such as the barrier ZDB. It is, theretore, expedient to provide the trackway dragging equip ment detector apparatus at relatively frequent intervals along the trackway so as to detect the presence of dragging equipment relatively soon after the equipment starts to drag, and before any material damage to the trackway or derailment of a train is liable to be effected.

Having described the mode of operation of the system for passage of a train in a given direction, it should be readily apparent that the symmetry of the organization is such that the same mode of operation as that described for one direction of traffic is accomplished for passage of a train in the opposite direction.

Having thus described a dragging equipment detector system as one embodiment of the present invention, it is desired to be understood that this form has been selected to facilitate in the disclosure of the present invention rather than to limit the number of forms which the present invention may assume, and it is to be further understood that various adaptations, alterations and modifications may be applied to the specific form shown to meet the requirements of practice, without in any manner departing from the spirit or scope of the present invention except as limited by the appending claims.

What I claim is:

l. A dragging equipment detector control system for trains passing over a stretch of railway track comprising in combination, detector means disposed at intervals along the trackway and subject to actuation by equipment dragging beneath a railway car, an inductor located along the trackway for each detector means, circuit means for shunting each of the inductors except when said detector means is actuated, train carried receiving means subject to actuation when a train passes over said inductor only if said inductor is unshunted, and means for automatically resetting said detector means subsequent to its actuation after passage of a train.

2. A dragging equipment detector control system fo1 trains comprising in combination, a stretch of railway track, said stretch of track being divided into pairs of adjoining track sections, a plurality of detector means disposed at intervals along the trackway and subject to actuation by equipment dragging from beneath a railway car, an inductor disposed along the trackway for each detector means, said inductors being located at the adjoining ends of the respective pairs of track sections, circuit means for normally shunting each of the inductors, circuit means effective when said detector means is actuated for unshunting its associated inductor only provided 6 that both of the associated adjoining track sections are occupied at the time when the detector means is actuated, and train carried receiving means subject to actuation whenever the train passes over an inductor that is un shunted.

3. A dragging equipment detector control system for trains passing over a stretch of railway track comprising in combination, a detector barrier disposed across the track, said detector barrier being biased to a vertical position from which it is subject to actuation by dragging equipment, a contacter having a normally closed contact subject to actuation in accordance with the actuation of said barrier, two adjoining track circuits in said stretch of track having respective track relays, a dragging equipment detector relay, circuit means for energizing said detector relay when either of said track relays is energized, stick circuit means including said contact of said contactor for maintaining said detector relay energized, an inductor associated with said stretch of track at the adjoining ends of said adjoining track sections, circuit means for shunting said inductor when said detector relay is energized, a train carrier receiver subject to actuation when passing over said inductor if the shunt on said inductor is removed, and train carrier signaling means for indicating the actuation of said receiver.

4. A dragging equipment detector control system for trains passing over a stretch of railway track divided into two adjoining track sections comprising in combination, a track circuit including a track relay for each of the track sections, detector means disposed across the trackway having a normally closed contact subject to actuation by equipment dragging beneath a train, a dragging equipment detector relay, means for energizing said detector relay when either or both of said track relays is energized, stick circuit means including said contact of said detector means for maintaining said detector relay energized, an inductor disposed along the trackway at the adjoining ends of said adjoining track sections, means including said detector relay for selectively shunting and unshunting said inductor, and train carrier receiving means subject to actuation when a train passes over said inductor only if said inductor is unshunted.

5. A dragging equipment detector control system for trains passing over a stretch of railway track comprising in combination, detector means disposed along the trackway and subject to actuation by equipment dragging beneath a railway car, an inductor disposed along the trackway near said detector means, circuit shunting means governed by said detector means and acting on the winding of said inductor when said detector means is in its normal condition to render said inductor ineffective but acting on said winding to unshunt said inductor elective whenever said detector means has been actuated from its normal condition by dragging equipment, and train carried control receiving means emitting energy of a distinctive character and disposed near the rear end of a train, said receiving means adapted to pass through an inductive coupling relationship with said inductor during passage of said train, said train carried receiving means receiving a distinctive control from said inductor upon passing over said inductor provided said inductor has been rendered effective by said circuit means.

References Cited in the le of this patent UNITED STATES PATENTS 2,063,336 Post Dec. 8, 1936 

